Hesperocyparis arizonica, the Arizona cypress, is a North American species of tree in the cypress family Cupressaceae, native to the southwestern United States and Mexico. Populations may be scattered rather than in large, dense stands.
| Hesperocyparis arizonica | |
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| Hesperocyparis arizonica (Arizona cypress) foliage and cone | |
Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Cupressales |
| Family: | Cupressaceae |
| Genus: | Hesperocyparis |
| Species: | H. arizonica
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| Binomial name | |
| Hesperocyparis arizonica (Greene) Bartel
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| Natural range of Hesperocyparis arizonica | |
| Synonyms[3] | |
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List
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Description
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Hesperocyparis arizonica is a coniferous evergreen tree with a conic to ovoid-conic crown. It grows to heights of 10–25 m (33–82 ft), and its trunk diameter reaches 55 cm (22 in). The foliage grows in dense sprays, varying from dull gray-green to bright glaucous blue-green. The leaves are scale-like, 2–5 mm long, and produced on rounded (not flattened) shoots. The seed cones are globose to oblong, 15–33 mm long, with 6 or 8 (rarely 4 or 10) scales, green at first, maturing gray or gray-brown about 20–24 months after pollination. The cones remain closed for many years, only opening after the bearing branch is killed (in a wildfire or otherwise), allowing the seeds to colonize the bare ground exposed by the fire. The male cones are 3–5 mm long, and release pollen in February–March.[4]
Taxonomy
editHesperocyparis arizonica was given its first scientific name and described by Edward Lee Greene in 1882 as Cupressus arizonica, placing it in genus Cupressus.[3][5] This description was soon after disputed by Maxwell T. Masters who, in 1896, published a journal article where he said it should be considered a subspecies of Cupressus benthamii with the variety name of arizonica.[3] A similar classification reducing it to a subspecies as Cupressus lusitanica subsp. arizonica was posthumously published by René Maire in 1952.[3] There also have been publications that suggested moving it as a species to a different genus such as Callitropsis in 2006 and a new genus, Neocupressus, in 2009.[3]
As of 2024 Plants of the World Online (POWO), World Flora Online (WFO), and the USDA Natural Resources Conservation Service PLANTS database (PLANTS) list H. arizonica as the correct species name.[3][6][7] This classification was published by Jim A. Bartel in 2009.[3] However, Cupressus continues to be used in professional papers by some scientists.[8][9]
Other disagreements have been over the validity of various subspecies of H. arizonica. A total of eleven have been validly published. However seven of these are listed as synonyms by POWO and WFO as of 2024.[3][6] The remaining four are listed as separate species:
- Hesperocyparis glabra formerly Cupressus arizonica var. glabra – Smooth Arizona cypress[10]
- Hesperocyparis montana formerly Cupressus arizonica var. montana – San Pedro Mártir cypress[11]
- Hesperocyparis nevadensis formerly Cupressus arizonica var. nevadensis – Paiute cypress[12]
- Hesperocyparis stephensonii formerly Cupressus arizonica var. stephensonii – Cuyamaca cypress[13]
Distribution
editHesperocyparis arizonica is found mainly in northern Mexico in the states of Chihuahua, Coahuila, Durango, Tamaulipas, and Zacatecas. It is also found in small areas of the southwestern United States in the southern parts of Arizona, New Mexico, and Texas. In the US it is found between 1000 and 1500 meters in elevation while in Mexico it reaches as high as 2200 meters in some forests.[14][3] In the wild, the species is often found in small, scattered populations, not necessarily in large forests. An example occurrence is within the Sierra Juárez and San Pedro Mártir pine–oak forests of Mexico,[15] where it is found along with canyon live oak and California fan palm.
Uses
editArizona cypress is widely cultivated as an ornamental tree. Unlike Monterey cypress, it has proved highly resistant to cypress canker, caused by the fungus Seiridium cardinale, and growth is reliable where this disease is prevalent.
The cultivar 'Pyramidalis'[16] has gained the Royal Horticultural Society's Award of Garden Merit (confirmed 2017).[17]
Example of neoendemism and conservation challenges
editThe ease of hybridization of western cypress species in the American southwest has fostered a parallel history of taxonomic disagreements of where genus and species distinctions should apply. [18] It thus provides a case study of neoendemism in conifers. Close taxonomic relatedness, in turn, offers both challenges and opportunities if and when assisted migration is considered as a mode of climate adaptation to prevent extinctions of endemic cypresses in the American southwest.[19]
References
edit- ^ Farjon, A. (2013). "Cupressus arizonica". IUCN Red List of Threatened Species. 2013: e.T42216A2962318. doi:10.2305/IUCN.UK.2013-1.RLTS.T42216A2962318.en. Retrieved 12 November 2021.
- ^ NatureServe (2024). "Cupressus arizonica". Arlington, Virginia. Retrieved 28 January 2024.
- ^ a b c d e f g h i "Hesperocyparis arizonica (Greene) Bartel". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 27 January 2024.
- ^ Eckenwalder, James E. (1993). "Cupressus arizonica". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 2. New York and Oxford: Oxford University Press – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- ^ Greene, Edward Lee (May 1882). "New Western Plants". Bulletin of the Torrey Botanical Club. 9 (5). New York: Torrey Botanical Club: 64–65. Retrieved 27 January 2024.
- ^ a b "Hesperocyparis arizonica (Greene) Bartel". World Flora Online. Retrieved 27 January 2024.
- ^ Hesperocyparis arizonica, USDA Natural Resources Conservation Service PLANTS Profile, 13 February 2024
- ^ Michalet, Richard; Carcaillet, Christopher; Delerue, Florian; Domec, Jean-Christophe; Lenoir, Jonathan (19 December 2023). "Assisted migration in a warmer and drier climate: less climate buffering capacity, less facilitation and more fires at temperate latitudes?". Oikos. doi:10.1111/oik.10248. S2CID 266410521. Retrieved 13 February 2024.
- ^ Raddi, Paolo; Della Rocca, Gianni; Danti, Roberto (8 January 2020). "Cupressus glabra". In Stimm, B.; Roloff, A.; Lang, U.M.; Weisgerber, H. (eds.). Enzyklopädie der Holzgewächse: Handbuch und Atlas der Dendrologie /begründet von Peter Schütt. Andreas Roloff; Horst Weisgerber; Ulla M. Lang; Bernd Stimm. Weinheim: Wiley-VCH. ISBN 9783527321414.
- ^ "Hesperocyparis glabra (Sudw.) Bartel". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 27 January 2024.
- ^ "Hesperocyparis montana (Wiggins) Bartel". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 27 January 2024.
- ^ "Hesperocyparis nevadensis (Abrams) Bartel". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 27 January 2024.
- ^ "Hesperocyparis stephensonii (C.B.Wolf) Bartel". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 27 January 2024.
- ^ Earle, Christopher J. (3 March 2023). "Cupressus arizonica (Arizona cypress) description". The Gymnosperm Database. Retrieved 28 January 2024.
- ^ National Geographic 2001.
- ^ "RHS Plant Selector – Cupressus arizonica 'Blue Ice'". Retrieved 15 April 2020.
- ^ "AGM Plants – Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 26. Retrieved 24 January 2018.
- ^ Rehfeldt, Gerald E (1997). "Quantitative analyses of the genetic structure of closely related conifers with disparate distributions and demographics: the Cupressus arizonica (Cupressaceae) complex". American Journal of Botany. 84 (2): 190–200. doi:10.2307/2446080. JSTOR 2446080. PMID 21712198.
- ^ Barlow, Connie. "Climate, Trees, and Legacy: 04 - Lessons of Arizona Cypress". youtube. ghostsofevolution. Retrieved 14 December 2022.
Further reading
edit- World Wildlife Fund, ed. (2001). "Sierra Juarez and Sierra Pedro Martir Pine-oak Forests". WildWorld Ecoregion Profile. National Geographic Society. Archived from the original on 2010-03-08.
- Farjon, A. (2013). "Cupressus arizonica". IUCN Red List of Threatened Species. 2013: e.T42216A2962318. doi:10.2305/IUCN.UK.2013-1.RLTS.T42216A2962318.en. Retrieved 12 November 2021.
External links
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- USDA Plants Profile for Hesperocyparis arizonica (Arizona cypress)
- Calflora as Hesperocyparis stephensonii
- Jepson eFlora, The Jepson Herbarium, University of California, Berkeley as Hesperocyparis stephensonii
- Hike Arizona.com: Photos of Arizona Cypress (Cupressus arizonica)
- Cupressus arizonica in the CalPhotos photo database, University of California, Berkeley